Fuel oil and method of operating fuel oil furnaces



. 3, 1963 A. w. PERCY ETAL FUEL OIL AND METHOD OF OPERATING FUEL OILFURNACES Filed Dec. 26, 1957 0 =0 20 000 000 -00 000 000 000 000 -00 .000 0 W m a. 3; 5 0 000 M 000 W 1 SO G M 0w 6 x, I m 50 u. a 8 2.: a5. 303 V .IG- 0 H H V k a w N N wm m m =O 4min N 025: mhmuh ISO: 130m muzmnmZMxSE.

INVENTORS ALLAN W PERCY BY WILLIAM J ZOLLINGER United States PatentOfifice 3,1 raise Patented Dec. 3, i003 3,112,789 FUEL GEL AND METHGD FOPERATING FUEL 01L FURNAQES Alian W. Percy and William J. Zoilinger,Crystal Lake,

llL, assignors to The Pure Oil Company, Chicago, EL,

a corporation of Ohio Filed Dec. 26, 1957, Ser. No. 705,301 Claims. (Cl.158117.5)

This invention relates to new and useful improvements in fuel oils andmore particularly to petroleum oils which are used in furnace-oilburners, which oils contain a novel fuel additive for mitigatingformation of sooty and carbonaceous deposits in the burner.v

A problem frequently encountered in the use of petroleum burner fuels,e.g., #2 or #3 fuel oils, in furnaces is the accumulation of sootydeposits on boiler walls. A further problem is the accumulation ofdeposits on the flame rim of rotary oil burners and on the nozzle faceof gun-type burners. Petroleum fuel oils also present the problem ofexcessive tendency to form very dense black smoke unless a substantialexcess of combustion air is used.

It is therefore one object of this invention to provide a new andimproved fuel oil composition which burns more completely and produceslesser amounts of carbonaceous and sooty deposits.

Another object of this invention is to provide an improved fuel oilhaving an additive which mitigates formation of sooty and carbonaceousdeposits and produces less dense smoke with smaller amounts ofcombustion air.

A feature of this invention is the provision of an improved fuel oilcomposition consisting of a burner oil boiling above the gasolineboiling range and containing a small quantity of manganese in the formof an oil-soluble manganese compound of the group consisting of indenylmanganese tricarbonyl, cyclopentadienyl manganese tricarbonyl, and alkylderivatives thereof.

Another feature of this invention is the provision of a novel fuel oilcomposition consisting of a #2 or #3 burner oil containing 0.00125 to0.005% w. of manganese as an oil-soluble manganese compound of the groupconsisting of indenyl manganese tricarbonyl, cyclopentadienyl manganesetricarbonyl, and alkyl derivatives thereof, which producess less densesmoke and less carbonaceous deposits while utilizing smaller amounts ofcombustion air.

A further feature of this invention is the provision of an improvedmethod of operating an oil burning furnace with dense smoke whichcomprises burning in the furnace a fuel oil containing an oil-solublecyclopentadienyl manganese tricarbonyl or derivative thereof.

Other objects and features of this invention will become apparent fromtime to time throughout the specification and claims as hereinafterrelated.

In the accompanying drawing there is shown a graph of boiler walldeposits, flame rim deposit-s, and smoke density vs. fuel compositionfor fuel oils prepared in accordance with this invention.

This invention is based upon our discovery that the addition of verysmall amounts of oil-soluble manganese compounds of the class consistingof indenyl manganese rioarbonyl, cyclopentadienyl manganese tricarbonyl,and alkyl derivatives thereof produces a fuel oil which results ingreatly decreased carbonaceous deposits in the burner and reduced smokedensity. This invention is more particularly concerned withour discoverythat a very small but critical proportion of the manganese compound willproduce the desired effect. It is only when the additive is used in amanganese concentration of 0.00125 to 0.005% by weight that theadvantages of this invention are realized.

In demonstrating this invention a number of tests were made using a #2furnace oil both with and without additives. The furnace oil usedconsisted of 65% by volume of fluid-catalytic-cracked light cycle oil,30% by volume kerosene, and 5% by volume virgin distillate fuel oil.This fuel oil was burned in a Timken wall-flame burner for 4 hours andwas found to produce carbonaceous deposits on the boiler wall averaging0.017" in thickness, and 0.0421 g. of carbonaceous deposits on the flamerim. In burning this oil it was necessary to use 60% excess air overstoichiomctric proportions to obtain an acceptable smoke density of #3on the Bacharach scale after 123-second sampling period. Under theseconditions of operation, the boiler etliciency was 75.2%.

A number of fuel oil compositions were prepared using the #2 furnace oilpreviously described to which there was added from 0.001 to 0.1% byweight of manganese, as the oil-soluble manganese compound, methylcyclopentadienyl manganese tricarbonyl. A number of test runs of 4 hoursduration each were made in the Timken burner using different fuel oilcompositions containing various amounts of the manganese-containingadditive. The results of several separate runs using different fuelcompositions are set forth in Table I.

TABLE I Boiler Wall Deposits, thickness, inches Flame dc-Concentration,-Wt. percent Mn posits, grams From these and otherexperiments we have found that fuel oil compositions containing 0.00125to 0.00 5 by weight of manganese result in reduced deposits in theburner and reduced smoke density. At manganese concentrations of theorder of 0.001% and less, and concentrations greater than 0.005%, themanganese additive increases the amount of burner deposits rather thanmitigating deposits.

Additional test runs were made in the Tiinken burner using the #2 burneroil with diiferent additive concentrations and with different amounts ofcombustion air. It

was found that the optimum concentrations of the additive is in therange of about 0.003 to 0.005% by weight of manganese. In that rangethere is obtained a substantial mitigation of deposits together with amaximum reduction in smoke density. Outside the range of 0.003 to 0.005%of manganese there is some improvement in the amount of deposits, but atthe cost of greater smoke density. In the 4-hour Tirnken burner tests, afuel composition consisting of a #2 burner oil containing methylcyclopentadienyl manganese tricarbonyl in a concentratio of 0.004% byweight of manganese produced an reduction in lower boiler-wall deposits,a 40% reduction in smoke density and a very slight increase in flame-rimdeposits compared to the base fuel oil. In series of test runs using thebase fuel oil alone, and the base fuel oil plus methyl cyclopentadienylmanganese tricarbonyl at a concentration of 0.003% by weight ofmanganese, and using different amounts of combustion air, it was foundthat the base fuel oil without any additive requires 60% excess air overthe stoichiometric amount to obtain an acceptable smoke level of #3 onthe Bacharach scale after a 123-second sampling period. Using the samefuel with the manganese additive at a concentration of 0.003% by weightof manganese, it was possible to operate the furnace at an acceptablesmoke level of #3 Bachar ach with only 28% excess air. The combinationof lower sensibleheat loss at this combustion air setting, reducedburner deposits, and improved combustion efficiency resulted in a boilerefficiency of 79.6% as compared to 75.2% efficicncy for the base fueloil without any additive. This operation of the furnace with the fueloil containing 0.003% by Weight of manganese with the lower amount ofcombustion air results in a saving of about 6% in fuel cost. Our testsindicate that burner fuel oils containing the manganese additive inconcentrations of 0.003 to 0.005% by weight of manganese produce smokehaving a density less than about #3 on the Bacharach scale (123- secondsampling period) when burned with 125 to 140% of the stoichiometricamount of air.

The improved combustion of fuel oils containing these oil-solublemanganese additives is also obtained when these oils are used ingun-type oil burners. This improved combustion, reduction in boilerdeposits, and reduction in smoke density is also obtained with otheroilsoluble cyclopentadienyl manganese tricarbonyl additives. Otheroil-soluble manganese additives which may be used in this invention areindenyl manganese tricarbony, cyclopentadienyl manganese tricarbonyl,and other alkyl-substituted cyclopentadienyl manganese trioarbonylswhich may contain any alkyl substituent which does not render thecompound insoluble in oil. These additives, when added to a fuel oil atconcentrations corresponding to 0.00125 to 0.005% by weight ofmanganese, result in a fuel oil composition having all of the advantagesdescribed above.

While we have fully and completely described our invention withparticular emphasis upon several preferred embodiments thereof, we wishit understood that within the scope of the appended claims thisinvention may be practiced otherwise than as specifically described.

What is claimed is:

1. A fuel oil composition consisting essentially of a furnace gradeheating oil containing an amount not substantially less than 0.003% w.and not substantially more than 0.005% W. of manganese as an oil-solublemanganese compound of the group consisting of indenyl manganesetricarbonyl, cyclopentadienyl manganese tricarbonyl, and alkylderivatives thereof.

2. A fuel oil composition in accordance with claim 1 in which themanganese compound is indenyl manganese tricarbonyl.

3. A fuel oil composition in accordance with claim 1 in which themanganese compound is cyclopentadienyl manganese tricar-bonyl.

4. A fuel oil composition in accordance with claim 1 in which themanganese compound is methylcyclopentadienyl manganese tricarbonyl.

5. A fuel oil composition in accordance with claim 1 in which themanganese compound is methylcyclopentadienyl manganese tricarbonyl andis present at a manganese concentration of 0.003 to 0.005% by weight.

6. A fuel oil composition in accordance with claim 1 in which theheating oil is a #2 furnace oil.

7. A method of operating an oil burning furnace with reduced amounts ofcarbonaceous deposits and producing smoke having a density less thanabout #3 on the Bacharach scale, 123-second sampling period, whichcornprises burning a fuel oil as defined in claim 5 with 125 to of thestoichiometric amount of air.

8. A method of operating an oil burning furnace with reduced amounts ofcarbonaceous deposits and producing smoke of low density which comprisessimultaneously metering a furnace grade heating oil and an amount notsubstantially less than 0.003% W. and not substantially more than 0.005%W. of manganese of a compound of the group consisting of indenylmanganese tricarbonyl, cyclopentadienyl manganese tricarbonyl, and alkylderivatives thereof, to said furnace, and burning the oil and manganesecompound in said furnace using a small stoichiometric excess of air.

9. A fuel oil composition consisting essentially of liquid hydrocarbonfuel oil suitable for use as a furnace heating oil containing, in anamount sufficient to reduce carbonaceous deposits, an oil-solublemanganese compound selected from the group consisting of indenylmanganese tricarbonyl, cyclopentadienyl manganese tricarbonyl, and alkylderivatives thereof.

10. A fuel oil composition consisting essentially of a furnace gradeheating oil containing in an amount sufficient to reduce carbonaceousdeposits and smoke an oil-soluble manganese compound selected from thegroup consisting of indenyl manganese tricarbonyl, cyclopentadienylmanganese tricarbonyl, and alkyl derivatives thereof.

References Cited in the file of this patent UNITED STATES PATENTS2,818,416 rown et al. Dec. 31, 1957 2,818,417 Brown et a1. Dec. 31, 19572,839,552 Shapiro et al. June 17, 1958 FOREIGN PATENTS 1,140,411 FranceMar. 4, 1957 OTHER REFERENCES Chemical and Engineering News, vol. 33,No. 16, Apr. 18, 1955, page 1645.

8. A METHOD OF OPERATING AN OIL BURNING FURNACE WITH REDUCED AMOUNTS OFCARBONACEOUS DEPOSITS AND PRODUCING SMOKE OF LOW DENSITY WHICH COMPRISESSIMULATANEOUSLY METERING A FURNACE GRADE HEATING OIL AND AN AMOUNT NOTSUBSTANTIALLY LESS THAN 0.003%W. AND NOT SUBSTANTIALLY MORE THAN0.005%W. OF MANGANESE OF A COMPOUND OF THE GROUP CONSISTING OF INDENYLMANGANESE TRICARBONYL, CYCLOPENTADIENYL MANGANESE TRICARBONYL, AND ALKYLDERIVATIVES THEREOF, TO SAID FURNACE, AND BURNING THE OIL AND MANGANESECOMPOUND IN SAID FURNACE USING A SMALL STOICHIOMETRIC EXCESS OF AIR.